One‐Pot Synthesis of Highly Substituted Polyheteroaromatic Compounds by Rhodium(III)‐Catalyzed Multiple C?H Activation and Annulation

A new method for the synthesis of highly substituted naphthyridine‐based polyheteroaromatic compounds in high yields proceeds through rhodium(III)‐catalyzed multiple C H bond cleavage and C C and C N bond formation in a one‐pot process. Such highly substituted polyheteroaromatic compounds have attracted much attention because of their unique π‐conjugation, which make them suitable materials for organic semiconductors and luminescent materials. Furthermore, a possible mechanism, which involves multiple chelation‐assisted ortho C H activation, alkyne insertion, and reductive elimination, is proposed for this transformation.     

Direct generation of a 10 GHz 816 fs pulse train from an erbium-fiber soliton laser with asynchronous phase modulation

By employing the technique of asynchronous mode locking, we have successfully demonstrated direct generation of stable 10 GHz 816 fs pulse trains with a supermode-suppression ratio >70 dB from a hybrid mode-locked Er-fiber laser. When the modulation frequency deviates from the cavity harmonic frequency by 15-40 kHz, stable femtosecond soliton pulses are formed. Our results demonstrate that asynchronous mode locking can act as an effective mechanism for achieving a shorter pulse width and for stabilizing high-repetition-rate pulse trains in soliton fiber lasers.     

Quantitative enantiomeric analysis of chlorcyclizine,hydroxyzine, and meclizine by capillary electrophoresis

A simple capillary zone electrophoresis method was developed for the quantitative enantiomeric analysis of piperazine antihistamines with teratogenic suspicion in animals. Enantioseparation of chlorcyclizine, hydroxyzine, and meclizine was performed in glycine buffer (0.6 mol L^-1; pH 3.00) with sulfated -cyclodextrin (5 mg mL^-1) as a chiral selector; and the separated drugs were monitored by ultra-violet detector. The lower quantitation of the individual enantiomer is attainable at 10 µmol L^-1, using an achiral piperazine drug (cyclizine) as internal standard. The method is simple and rapid with a short run time (<5 min) for the analysis of chlorcyclizine, hydroxyzine or meclizine enantiomers.     

A Facile Synthesis and Structural Verification of Etorphine and Dihydroetorphine from Codeine

In this study, an improved process for the synthesis of etorphine and dihydroetorphine from codeine with an overall yield of 2.7% and 1.5% respectively is described. The structure of 19‐propylthevinol 7 was verfied by X‐ray structure analysis. This result is promising for synthesizing various morphine‐based drugs.     

JavaStatSoft: design patterns and features

JavaStatSoft, implemented using Java, is an open-source software for performing statistics. The current features of JavaStatSoft are described. Several well-known patterns the software used are introduced. In addition, based on these patterns and the experience in developing the software, a new framework, referred to as Data Analysis Module, is proposed to help programmers develop a user-friendly software for data analysis.     

Saccharomyces cerevisiae oxidosqualene‐lanosterol cyclase: A chemistry–biology interdisciplinary study of the protein's structure–function–reaction mechanism relationships

The oxidosqualene cyclases (EC 5.4.99‐) constitute a family of enzymes that catalyze diverse cyclization/rearrangement reactions of (3S)‐2,3‐oxidosqualene into a distinct array of sterols and triterpenes. The relationship between the cyclization mechanism and the enzymatic structure is extremely complex and compelling. This review covers the historical achievements of biomimetic studies and current progress in structural biology, molecular genetics, and bioinformatics studies to elucidate the mechanistic and structure–function relationships of the Saccharomyces cerevisiae oxidosqualene‐lanosterol cyclase‐catalyzed cyclization/rearrangement reaction. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 302–325; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20157     

<!?tlsb=‐0.06pt>Bromido(η5‐carboxycyclopentadienyl)dinitrosylchromium(0) and (η5‐benzoylcyclopentadienyl)bromidodinitrosylchromium(0)

In the structures of each of the title compounds, [CrBr(C₆H₅O₂)(NO)₂], (I), and [CrBr(C₁₂H₉O)(NO)₂], (II), one of the nitrosyl groups is located at a site away from the exocyclic carbonyl C atom of the cyclopentadienyl (Cp) ring, with twist angles of 174.5 (3) and 172.5 (1)°. The observed orientation is surprising, since the NO group is expected to be situated trans to an electron‐rich C atom in the ring. The organic carbonyl plane is turned away from the Cp ring plane by 5.6 (8) and 15.2 (3)°in (I) and (II), respectively. The exocyclic C—C bond in (I) is bent out of the Cp ring plane towards the Cr atom by 2.8 (3)°, but is coplanar with the Cp ring in (II); the angle is 0.1 (1)°.